Here's why this is a bit of a tricky question:
* Hair texture is a genetic trait: Hair texture is influenced by genetics. There are people with curly hair in Turkey, and there are people with straight hair in Turkey. It's like saying "Americans have blue eyes." Some do, some don't!
* Nationality doesn't determine physical traits: A person's nationality doesn't tell you what their hair texture, eye color, or any other physical characteristic will be.
Instead of making generalizations about a whole group of people, it's important to remember that individuals within any group are diverse.